MySQL Cluster Node Availability Test

This test reports the availability and responsiveness of each node in the cluster, and collects statistics pertaining to the query execution time on each node.

Target of the test : A MySQL Cluster

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each node on the target MySQL Cluster database server being monitored

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

The host for which the test is to be configured.

Port

The port at which the specified host listens.

Database

Specify the name of a database on the target MySQL Cluster database server being monitored

Username and Password

The eG agent has to be configured with the credentials of a user who has server-wide Process and Select privileges on the monitored MySQL Cluster database server. To know how to create such a user, refer to Pre-requisites for Monitoring the MySQL Cluster Database Server topic.

Confirm Password

Confirm the password by retyping it here.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Node availability

Indicates whether the cluster node is responding to requests.

Percent

The availability is 100% when a cluster node is responding to a request and 0% when it is not. Availability problems may be caused by a misconfiguration/malfunctioning of the node, or because the node is using an invalid user account. Besides the above, this measure will report that the server is unavailable even if a connection to the node is unavailable, or if a query to the node fails. In this case, you can check the values of the DB connection availability and Query processor availability measures to know what is exactly causing the node to not respond to requests - is it owing to a connection unavailability? or is it due to a query failure?

Node response time

Indicates the time taken by this node to respond to a user query. This is the sum total of the connection time and query execution time.

Seconds

A sudden increase in response time is indicative of a bottleneck at the node. This could even be owing to a connection delay and/or long running queries to the node. Whenever the value of this measure is high, it would be good practice to compare the values of the DB connection response time and Query execution time measures for a node to zero-in on the root-cause of the poor responsiveness of the server - is it because of connectivity issues? or is it because of inefficient queries?

DB connection availability

Indicates whether the database connection to this node is available or not.

Percent

If this measure reports the value 100, it indicates that the database connection is available. The value 0 on the other hand indicates that the database connection is unavailable. A connection to the database may be unavailable if the database is down or if the database is listening on a port other than the one configured for it in the eG manager or owing to a poor network link. If the Node availability measure reports the value 0, then, you can check the value of this measure to determine whether/not it is due to the unavailability of a connection to the server.

DB connection response time

Indicates the time taken to connect to the cluster node.

Seconds

A high value could indicate a connection bottleneck. Whenever the Node response time measure soars, you may want to check the value of this measure to determine whether a connection latency is causing the poor responsiveness of the node.

Query processor availablity

Indicates whether the query to this node is executed successfully or not.

Percent

If this measure reports the value 100, it indicates that the query executed successfully. The value 0 on the other hand indicates that the query failed. In the event that the Node availability measure reports the value 0, check the value of this measure to figure out whether the failed query is the reason why that measure reported a node unavailability.

Query execution time

Indicates the time taken for query execution on this node.

Seconds

A high value could indicate that one/more queries to the node are taking too long to execute. Inefficient/badly designed queries to the database often take too long to execute. If the value of this measure is higher than that of the Connection time measure, you can be rest assured that long running queries are causing the node to respond slowly to requests.

Number of records

Indicates the number of records fetched from the database for this node.

Number

The value 0 indicates that no records are fetched from the database.